Flow control or not, for sickle bar: Samuri/Sabre

[J_J]

This is one of the motors used.

2.8 cu in CHAR-LYNN 101-1001 HYD MOTOR

71 ft lbs of torque, continuous.

I would suspect the slower you run it, the larger branches you can cut. Which is why about 350 rpm or slower is recommend

At fast speeds, it may take a while to saw through the branch.

 

[Coyote machine]

Coyote machine, That is my problem, it squeals when I remove the sickle connection. At this point the flow should be stopped. When the sickle is connected it runs great. It would take more than my wimpy hydraulic knowledge to figure this thing out.

I'm not sure we're on the same page. I'm saying to avoid the squeal, remove the sickle bar AND the flow control valve as a complete combined unit, intended for sickle bar cutting only. That way, no overpressure, no need far a jumper from CF to EF, etc. Don't know if trying to remove all of it from the tractor would more difficult then just removal of the sickle bar since currently neither is in my possession yet.
It's an idea to consider though....


J_J and Spyderlk, what if anything can we conclude from what's been kicked around so far?

 

[J_J]

The people at Samurai did not call me back.

No idea why the 500 psi limit.

 

[SPYDERLK]

The people at Samurai did not call me back.

No idea why the 500 psi limit.

Theres no why. Its an error. ... One of typo, or due diligence in internal company analysis or communication.
,,,, Fortunately there is experience of users to rely on.
The cutter is not harmed by stall at 2600 relief setting.

 

[J_J]

Coyote machine ,

Here is the answer I obtained from the folks at Samuri.

The 500 psi is not a mistake.

The suggested 500 psi is there to prevent the torque from a high psi motor from destroying the blades and gearing.

So in order to limit the torque, you have to add an external relief valve across the motor.

If you don't limit the torque, you will be breaking , bending and ripping things apart.

Although they mentioned the 1 in material, they are talking about green material, not dried 1 in oak branches.

 

[SPYDERLK]

Coyote machine ,

Here is the answer I obtained from the folks at Samuri.

The 500 psi is not a mistake.

The suggested 500 psi is there to prevent the torque from a high psi motor from destroying the blades and gearing.

So in order to limit the torque, you have to add an external relief valve across the motor.

If you don't limit the torque, you will be breaking , bending and ripping things apart.

Although they mentioned the 1 in material, they are talking about green material, not dried 1 in oak branches.

TOTAL BS from the mfg. Based on their info it would be a mistake to buy the cutter. It wont cut anything of 1" diameter at 500 psi -- maybe milkweed :confused3:. And it is not harmed by the torque developed at 2500psi.
larry

 

[J_J]

I am not sure why you disagree with the guys that make the Samurai. [spelling] not sure.

I am sure they are cautious about the damage that could occur.

You probably will not be cutting 1in oak branches all the time, and even if you do, with no relief, the pressure could go as high as 2400 psi. The motor is rated to develop pressure in continuous work load of 1800 psi. It is also not just the motor. How about the mechanical parts in the head assembly, and the blades, can they take all the torque developed by the motor?

I think a few test cuts will help one decided if any relief should be added.

I wonder how many units that have been returned because of misuse and lack of operating procedures.

I think I would put a hyd gage on the unit and watch the pressure and what I am cutting to determine the best way to operate the sickle bar mower.

At $1450 I would be a little cautious.

 

[Coyote machine]

Hey guys, I'm back, and the sickle bar should arrive this coming Tuesday.
I'll keep you posted as to any concerns as I set-up the unit for my rig.
I'm not sure we're any closer to an answer to my original question than at the beginning of this thread, especially since the two opinions currently seem to be at opposite ends of the spectrum as to whether or not to restrict flow?!:confused2:

 

[J_J]

I think you will have to restrict flow as the blades will be moving to fast for efficient cutting.

You can vary the flow and speed of the tractor as you test the unit for the best operation.

The speed of operation will change as you cut various shrubbery and limbs.

I think the flow should be adjusted to let the material touch the base of the cutting bar for the best cutting technique.

The pressure will vary as you cut different material.

Torque should be constant throughout the cutting speed.

You don't want the woody material to ride on the tips of the cutting teeth.

Thats my story and I am sticking to it.

 

[SPYDERLK]

TOTAL BS from the mfg. Based on their info it would be a mistake to buy the cutter. It wont cut anything of 1" diameter at 500 psi -- maybe milkweed :confused3:. And it is not harmed by the torque developed at 2500psi.
larry

I am not sure why you disagree with the guys that make the Samurai. [spelling] not sure.

I am sure they are cautious about the damage that could occur.

You probably will not be cutting 1in oak branches all the time, and even if you do, with no relief, the pressure could go as high as 2400 psi. The motor is rated to develop pressure in continuous work load of 1800 psi. It is also not just the motor. How about the mechanical parts in the head assembly, and the blades, can they take all the torque developed by the motor?

I think a few test cuts will help one decided if any relief should be added.

I wonder how many units that have been returned because of misuse and lack of operating procedures.

I think I would put a hyd gage on the unit and watch the pressure and what I am cutting to determine the best way to operate the sickle bar mower.

At $1450 I would be a little cautious.

Its pretty obvious from my posts why I not only disagree, but call BS on their statements. - If you dont see it ask some questions. - The cutter wont do anything if limited to 500psi. If you believe them about damage at pressure anywhere near that limit you are essentially settling for a grass cutter if you plan to follow that guideline. The company is limiting its device to a worthless performance level. They are also throwing out chaff -- it has no gears to damage.

The cutter is capable of withstanding the force developed from the motor stalling on a 2600PSI relieved system if they havent downgraded it since I bought mine.

,,,,I dealt with the motor pressure issue earlier. :

Those are continuous use pressures. Intermittent is quite a bit higher. On the cutter the motor only sees hi pressure for an instant. Duty cycle at appreciable pressure is probably less than 0.1% and only a small fraction of a second at a time.